Characterization of petroleum saturates

A method for characterizing the saturates portion of a petroleum or hydrocarbon sample that includes compounds with boiling points of 1000° F. (538° C.) or higher includes use of laser desorption ionization (LDI) to desorb and vaporize petroleum saturates into the gas phase. After ionization, the saturate compounds cations can be detected using mass spectrometry. The mass spectrum generated from the ionized saturated compounds is then characterized by assigning molecular formulas to any “detected” masses that exhibit a peak with an intensity greater than a defined signal to noise threshold. After making the molecular assignments, the abundance of each assigned molecule can be determined based on the signal magnitude of the peaks in the mass spectrum. The assigned molecules and the corresponding abundances can then be grouped based on a variety of factors.